PI Controller in Matlab Model Function

How do I put this equation in to be able to use it in my model? This is the feedback input, so I need to use it in array form/time domain etc. Ive tried pid(). s=tf('s'), not really working:

deltaV=Gc*(1+Ki/s)*deltaPsi

ie deltaPsi is the feedback (from a state space model), Gc is some gain, 1/s is the integrator term but obvs just typing this in doesn't work